Patients and methods :all patients diagnosed with periampullar occupations which should be resected through pancreaticoduodenectomy will be evaluated before surgery, including CT,Magnetic Resonance(MR), Ultrasound B ,blood biochemical checks and cardiac and thoracical evaluations. Before the surgery, the patients are divided into two groups by randomization. After the pancreaticoduodenectomy, the randomization number decided the procedure of the pancreaticojejunostomy.